1. Field of the Invention
This invention relates to a uniform pressing apparatus, and more particularly to a uniform pressing apparatus for use in a micro-nano fabrication process.
2. Description of the Related Art
Referring to FIG. 1, a conventional uniform pressing apparatus for use in a micro-nano fabrication process includes a support unit 1 for supporting a substrate 6 to be imprinted, a mold 2 disposed on the substrate 6, a holder 3 disposed above the support unit 1, a driving unit 4 for moving the holder 3 vertically, and a uniform pressing member 5 held within the holder 3. The support unit 1 is operable to heat or cool the substrate 6. The uniform pressing member 5 includes a resilient film 501 made of a material capable of resisting high temperatures and high pressures, and a fluid 502 filled within the resilient film 501.
As such, when the driving unit 4 is operated to move the holder 3 downwardly to thereby press the uniform pressing member 5 against the mold 2, the uniform pressing member 5 applies a uniform pressure to the mold 2 so as to perform a nanoimprint operation on the substrate 6.
However, the aforesaid conventional uniform pressing apparatus suffers from the following disadvantages:                (1) The resilient film 501 is required to be made of a material capable of resisting high temperatures and high pressures. Such material is expensive which increases the manufacturing costs of the uniform pressing apparatus.        (2) Due to the use of the uniform pressing member 5 under high-temperature and high-pressure conditions, the service life of the resilient film 501 is short.        (3) The driving unit 4 is typically configured as a hydraulic or pneumatic cylinder, which enables only a limited pressure to be applied to the mold 2. Thus, when the substrate 6 is a thin metal plate, the pressure applied to press the mold 2 against the substrate 6 may be insufficient to provide complete imprinting on the substrate 6.        